Building contractors and others involved with replacing old stairways and building new stairways are constantly searching for ways by which to restore old and build new stairways. One situation that continues to repeat itself is that when an old stairway is removed, it is often the case that the metal or wood stringers can be reused, whereas the step supports, typically in the form of short pieces of right-angle metal strips fastened to the inside surfaces of the stringers, are in most cases replaced but in other cases are left in place for reuse. Thus, there is a need for being able to use existing stringers and either new or existing stair supports when a stairway is being replaced in an old building. One purpose of the invention thus becomes that of providing a component and method useful for restoring a stairway on existing stringers and on either new or existing stair supports.
The component and method of the invention, while primarily directed to use in conjunction with replacing old stairways, also finds application to the practice of building new stairways. In either case, the invention further recognizes the advantages of being able to either restore an old stairway or build a new stairway by use of relatively light weight, easily handled components that can be put together at the job site to build a stairway without the need for having to pour concrete to form steps, having to weld parts together, or having to use a crane to assist in building the stairway from a heavy assembly or heavy components as in many prior art practices. Furthermore, the invention provides for quick assembly, which is highly useful when restoring a stairway in a residential setting.
Recognizing that the invention is directed to a component, which can be joined to other components of similar construction for the purpose of building either a replacement or new  stairway, reference is next made to the following United States patents as being representative of known types of stairway components, which can be put together at the job site in order to build a replacement or new stairway, namely U.S. Pat. Nos. 2,193,146; 4,034,525; 4,343,120; 4,899,504; 5,794,391; 5,799,448; and Des. 389,588.
Another aspect of prior practices associated with the construction of stairways is the practice of installing a pan at the site of each step and filling the pan with concrete to form each individual step. U.S. Pat. No. 4,899,504 cited above illustrates this practice. In another practice illustrated by U.S. Pat. No. 2,193,146, the parts of the stairway are welded together at the job site to form an assembled stairway.
Another problem faced by those who construct new stairways on existing stringers is the fact that the spacing between the stringers will vary due to settling, misaligned building components, warping, and the like. Thus, the invention recognizes that the easily cut stairway component of the invention when cut to length at the site can be made to accommodate and adjust to different stringer spacings.
So far as is presently known, the prior art has not provided a component and method for restoring a stairway, and which are specifically adapted to make use of existing stringers, make use of either new or existing stair supports, and accommodate to varying space between the stringers.
With the above in mind, a principal object of the present invention is to provide a relatively light weight, relatively strong, self-supporting, ready-to-use, cut-to-length stairway component, which can be quickly installed on existing stringers having sets of either newly-installed or previously-installed stair supports on the interior faces thereof and engaged with portions of other components of similar construction to form a complete stairway and in a manner that accommodates to different spacings between existing stringers, that requires no  welding at the job site to complete construction of the component or addition of concrete to form a step on the component. Other objects will become apparent as the description proceeds.